Worst journey I ever had from the South coast up to Old Sarum, to hopefully spend a day instructing at 622 Gliding School, was in very thick fog. As the first instructor to arrive I sat in the office, totally unable to see the airfield only a few yards away, and called the RAF Met office at Upavon for the official gliding forecast. This meant that the Met man just read out the data on his form and I copied it onto mine. It was a wonderful forecast so I suggested to the met man that the fog would clear pretty quickly. He seemed totally surprised that we had any fog and that it wasn't particularly local.
To be fair, the fog cleared quite quickly and we enjoyed an excellent day gliding.